title: Evaluation of the Bio-Rad Multispot HIV-1/HIV-2 Rapid Test as an alternative to Western blot for confirmation of HIV infection.
abstract: BACKGROUND
  In the United States, a new HIV diagnostic algorithm has been proposed that uses an HIV-1/HIV-2 antibody differentiation immunoassay instead of Western blot or immunofluoresence for confirmatory testing.
  
  
  OBJECTIVE
  To evaluate the Multispot HIV-1/HIV-2 Rapid Test (Multispot) as an alternative to Western blot analysis for confirmation of HIV infection.
  
  
  METHODS
  A series of 205 serum and plasma specimens positive for HIV-1 or HIV-2 were used to compare the performance of Multispot to a standard HIV-1 Western blot. Positive samples included 63 specimens from patients>18 months of age, 33 proficiency survey specimens, and 109 specimens from nine commercial seroconversion and performance panels. In addition, 63 specimens from 51 HIV-exposed, uninfected children≤18 months of age in various stages of seroreversion and 192 HIV-negative samples were tested. Specimens were initially screened using a 4th generation HIV Ag/Ab Combo assay.
  
  
  RESULTS
  Multispot readily discriminated between individuals with HIV-1 or HIV-2 infection and those who were uninfected. Of the 205 samples repeatedly reactive by the 4th generation screening assay, infection status was correctly confirmed by Multispot in 83.9% (172/205) compared to 68.8% (141/205) for Western blot. Multispot detected HIV-1 earlier in 27.6% of low-titer antibody specimens called indeterminate by Western blot, and effectively reduced the number of indeterminate results in seroreverting HIV-1 exposed, uninfected infants and for HIV-2 infections misinterpreted as indeterminate or positive by HIV-1 Western blot.
  
  
  CONCLUSIONS
  Multispot offers speed and simplicity over Western blot and has an excellent performance for differentiation and confirmation of antibodies to HIV-1 and HIV-2.
authors.affiliation: Clinical Virology Laboratory and Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Cárdenas
authors.affiliation: Clinical Virology Laboratory and Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Eleonore
authors.initials: E
authors.lastname: Baughan
authors.affiliation: Clinical Virology Laboratory and Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA. Electronic address: hodinka@email.chop.edu.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Hodinka
mesh_terms: D000465:Algorithms; D015153:Blotting, Western / Q000379:methods; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D015483:HIV Antibodies / Q000097:blood*; D015658:HIV Infections / Q000175:diagnosis* / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000276:immunology; D015498:HIV-2 / Q000145:classification* / Q000276:immunology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012698:Serologic Tests / Q000379:methods; D013997:Time Factors; D014481:United States; D014773:Virology / Q000379:methods
chemical_list: D015483:HIV Antibodies
keywords: Algorithm; CAP; CRF; College of American Pathology; Diagnosis; HIV; Ind; ND; NR; Neg; Pos; R; Rapid test; Western blot; circulating recombinant forms; indeterminate; mo.; months; negative; nonreactive; not done; positive; reactive